Microlab > Application Notes

One of the most critical parameters in today's congested wireless networks is Passive InterModulation or as it is commonly known, PIM. Not only is it necessary to select properly designed and tested low PIM components, but they must also be connected to the interconnecting coaxial cable with the appropriate torque.

As systems become more and more complex, choosing how best to combine two or more RF signals has become a far more difficult question to answer, and this application article is intended to highlight the benefits of the many options available to today's system engineer.

Couplers and samplers are similar to power dividers in that they each divide an RF signal into two or more signals. However, power divider outputs are of roughly equal amplitudes; couplers and samplers have a main line with one or more auxiliary lines.

Combining different wireless carriers does not always mean using complex filters or acceptance of the 3 dB loss of hybrid combiners. The choice usually starts with considerations of the guard band between the signals and the acceptable limitations of passive intermodulation (PIM).

A wide and often confusing assortment of power dividing and combining methods are available to the system designer, each of which has its own attributes and deficiencies. In addition, the same component can often be used to both divide and combine. This application note is intended to guide the system designer in the selection of the optimum component for any particular need.

Mechanical tuning devices continue to be a necessary part of all well-equipped microwave laboratories as well as microwave systems. Their convenience, power handling ability and linear properties cannot be duplicated in comparable solid state devices. This paper provides and overview of these tuners, discusses recent design advances and describes some new exciting system applications.

Microlab Signal Tappers, also known as Signal Sampler, are very similar to directional couplers. The signal sampler extracts all signals regardless of the direction of flow. These include direct-coupled resistive samplers as well as electrostatic and electromagnetic probe samplers. Tappers are frequently used in Distributed Antenna Systems (DAS) and are available with either N or 7-16 mm DIN connectors.

Microlab has been focused on the Military and Defense markets since our inception in 1950. In spite of the emergence of wireless markets,a significant portion of our commitment and focus remain fixed on the high-reliability products and processes used in military and defense applications

Splitters are used extensively in wireless signal distribution networks, to split the base station transmitted signal, Tx, into many different paths to reach multiple antennas, and at the same time to transmit the signals received by the antennas, Rx, back to the base station receiver.

Defined as Terrestrial Trunked Radio the TETRA market place supports first responder and emergency radio requirements world wide. Microlab supports TETRA base station requirements with a full suite of passive RF components.

Microlab has been making passive components for the sub-systems and laboratory markets for over 50 years. Such experience has contributed to the design of a range of dedicated products meeting the special demands of the commercial wireless market.

The next big step in the wireless industry will be the jump to WiMAX. Identified as wireless "metropolitan area networks", WiMAX can provide broadband wireless access with a coverage radius of up to 30 miles. Microlab is supporting the roll-out of these WiMAX networks with broad band filter diplexers, splitters, combiners and directional couplers.